Embodiments of the invention relate generally to gaskets and, more particularly, to a gasket stop for attachment to a bolt hole of a gasket frame, such as a filter house frame.
Various machines and devices, including gas and steam turbines, employ gaskets and gasket frames for sealing components of the machine or device. Typically, gaskets are housed within some manner of the gasket frame, which secures the gasket in place within the machine or device. A rail 20 of a conventional gasket frame is shown in FIG. 1. As can be seen, bolt holes 22, 24, 26 are located along rail 20. A pair of rails will generally be placed along either side of a gasket and secured together by passing a bolt through each bolt hole 22, 24, 26, thereby securing the gasket between the rails. The gasket frame itself may be of any shape and therefore include any number of rails of various sizes and shapes, as will be recognized by one skilled in the art. For ease of description, only a single elongate rail 20 is shown.
In order to avoid overcompression of a gasket secured between a pair of rails 20, known gasket frames often employ gasket stops 10, 12 between bolt holes 22, 24, 26. Typically, such gasket stops 10, 12 comprise metal discs welded along a surface of rail 20. When a gasket is placed between a pair of rails 20, which are then secured with bolts through bolt holes 22, 24, 26, gasket stops 10, 12 prevent over-compression of the gasket as the bolts are tightened. Avoidance of compression of a gasket beyond its design compression limit is critical to obtaining and maintaining the desired seal.
However, the bolts securing the pair of rails 20 are often not tightened using a torque wrench or other device for applying a measured pressure. As a consequence, the bolts tend to be overtightened, resulting in bending or deflection of rail 20, as shown in FIG. 2. Portions of rail 20 adjacent bolt holes 22, 24, 26 are deflected along path A, toward the second of the pair of rails (not shown), as the bolts are tightened.
Typically, gasket frames will include hundreds of bolt holes and gasket stops, resulting in extensive and uneven bowing of the frame's rails 20. As a consequence, compression of the gasket is uneven along its length, resulting in a less efficient seal, an incomplete seal, or in some cases, a seal failure, any of which may damage or destroy the machine or device in which it is contained.